A millennium is:
- a period of 1,000 years
- the time when one period of 1,000 years ends and another begins

A lot of people around the world celebrated the end of 1999 and the beginning of 2000. This was a special occasion because it was considered to be:

- the start of a new YEAR - the start of a new DECADE (10 years) - the start of a new CENTURY (100 years) - the start of a new MILLENNIUM (1000 years)

But not everyone agrees that 1 January 2000 was the first day of the new century/millennium. Some people say that the real first day was on 1 January 2001. Why do they say this? Their logic is very simple: we start counting from 1, not from 0, so:

- the first century ran from the year 1 to the year 100 - the last century ran from 1901 to 2000 - the present century runs from 2001 to 2100 - the next century will run from 2101 to 2200

This debate is a little academic because for much of the world the year is not the same as that of the "Christian calendar". The Christian calendar is the official calendar used by many countries. But there are other calendars, with different years. And their years do not always start on 1 January. During the Christian year 2000 we saw, for example:

- the start of Chinese year 4698 - the start of Islamic year 1421 - the start of Jewish year 5761

When did the Millennium start?

The millennium officially started on 1 January 2001.

Where did the Millennium start?

The millennium started in Greenwich (near London, England). This is because in 1884 at an International conference in Washington, DC, USA it was agreed to have a Universal Day. The day begins at the Prime Meridian of the World (Zero Longitude). This is the Greenwich Meridian, an imaginary line from North Pole to South Pole running through the telescope at the Royal Observatory in Greenwich. Consequently every day starts in Greenwich, including 1 January.

Where was the first sunrise of the Millennium?

A lot of countries said they had the first sunrise of the millennium. But if you had really wanted to see the first sunrise you would have had to go to Antarctica.